We show that the creation of selective sites on MoO3 due to remote control effects, has, as a counterpart, the spillover-induced reconstruction of the non-selective (010) faces of MoO3 crystals in selective (100) pits and steps. The phenomenon is observed both at the micrometric scale, by SEM, and at the nanometric scale, by AFM. (C) 1997 Elsevier Science B.V.